I installed a 80s chevy G30 truck master w/ a 7" universal corvette style booster under the floor of a 52' 4400. Installed new wheel cylinders and shoes on the 14" drums. the GVW is 14,000, and the truck stops like new ,even with a huge load of wood.. Very little rework on the brake lines and the master ended under the seat, but its worth the trouble.